The present disclosure relates to electronic circuits, and in particular, systems and methods for sharing bias current in electronic circuits.
Electronics systems and devices use ever increasing numbers of active devices (e.g., transistors). Active devices are typically operated with a bias current, which results in power usage. For integrated circuits in which low power consumption is desired, the overall contribution of the bias currents from many individual devices can result in undesirably high power usage, even when the integrated circuit is merely powered on in an idle state.
Power consumption is a particularly important problem in RF amplifiers. Many wireless systems run on batteries or other limited power supplies, such as a solar cell. If an RF amplifier consumes large amounts of current, it may reduce the operating lifetime of the system. In many RF amplifier designs, different amplification stages are each separately connected to a power supply rail. Thus, active devices in each stage each draw bias current which may be added together to determine a total bias current for an amplifier, for example. Given the performance demands on such circuits, the total bias current in an RF amplifier may be very high, which results in a correspondingly high power load on energy systems that provide power to circuitry in the system.